Figure 1

Perosomus elumbis in Holstein calves. Body parts caudal to the thoracic spine are dysplastic due to absence of lumbar, sacral and coccygeal vertebrae. The posterior limbs have bilateral symmetric flexion of the knee and hock joints and extension of the pastern joints with extensive muscular atrophy. Notice that the severity of hind limb malformation varies between cases. a and b represent cases DK1 and DK2, respectively.